Belt sanders



Dec. 9, 1969 1 c. E. Moor-EY y 3,482,358

' BELT SANDERS Filed sept. y27", '1967 cLiFFoRD EUGENE MooNEY.

ATTORNEY.

United States Patent O 3,482,358 BELT SANDERS Clifford Eugene Mooney, Atlanta Road,

Flowery Branch, Ga. 30542 Filed Sept. 27, 1967, Ser. No. 670,900

Int. Cl. B24b 21/00 U.S. Cl.51138 6 Claims ABSTRACT oF THE DISCLOSURE Apparatus for the treatment of wood and for the finishing and shaping of wood surfaces nudergoing the action of an abrasive belt while the belt is moving in a direction contrary to the movement of the piece of work passing through the machine.` A power driven rotary brush is so mounted that it may exert pressure on the abrasive belt whereby the pressure of the abrasive belt against the piece of work may be regulated. A graphited canvasmembrane is between the brush and the abrasive belt to eliminate the frictional drag on the brush such as would be present if the brush contacted the abrasive belt directly. Also the membrane softens the impact of the brush on the abrasive belty The brush is mounted on a pivoted member, the position of which is actuated by a cylinder which is subject to a limit switch manipulated by contact with the work piece.

This invention relates to a machine for abrading stock of the general character of wood, whether the work piece be of plywood or solid, or flat or contoured. Sensitive control of the operation of an abrasive belt on the work piece is obtained by exerting pressure on the non-abrasive side of the belt and the thrust of the abrasive surface against the work piece by invoking the use of a rotatable brush which is located between the runs of the abrasive belt which is mounted over a drive pulley and a driven pulley which are spaced apart.

The obvious purpose of using the brush is to produce a desired abrasive action on the entire surface of the stock consisting of the work piece regardless of the irregularity of the wooden stock.

Control of the driving action on the brush is made possible by the use of a limit switch which engages the work piece and which limit switch controls the actuation of a cylinder through suitable linkage to raise and lower the brush.

It will be manifest that the cylinder which is actuated by a limit switch may serve to control the dubbing of stock and the brush cannot be lowered into contact with the abrasive belt when there is no work in the machine.

The foregoing and additional features of this belt type sander will be understood from the following specification and claims when considered in conjunction with the accompanying drawing in which:

FIGURE 1 illustrates a side view of a machine for moving a work piece lengthwise with respect to a stock guide under the feeding action of a feed belt while abrasive treatment is applied to an abrasive belt on the upper surface of the work piece. The parts illustrated are adapted to be mounted on a conventional frame, which is not i1- lustrated so that the essential features of the improvement can most clearly be shown.

FIGURE 2 is a plan view taken on the line 2--2 of FIGURE 1 looking in the direction of the arrows at the upper and non-abrading surface of the lower run of the abrasive belt; and

FIGURE 3 is an enlarged side view of a portion of the machine in the region of the brush.

Referring in greater detail to the figures inthe drawing, 1 indicates an endless feed belt which is mounted for con tinuous movement over pulley wheels 2 and 3. These pulley wheels 2 and 3 may be idler pulleys if the work ICC piece 4 is advanced by mechanical means or either of the wheels 2 and 3 may be rotated by power. The work piece 4 is confined in its proper direction by a stock guide 5 conventionally.

Abrasive action for treatment of the work piece is provided by an abrasive belt 6 which extends parallel to the stock guide and work piece and is mounted on two spaced pulley wheels 7 and 8, of which 7 is the drive pulley and 8 is the driven pulley. In this arrangement the abrasive face of the abrasive belt 6 is downward.

.One of the useful features of this machine pertains to the use of a graphited canvas membrane belt 9 positioned next above the non-abrasive surface of the belt 6. This membrane 9 is fed from a roller 10 on a level parallel with the llevel of the belt 6 and is re-wound on a collecting roller 11. The membrane 9 can be adjusted but is not power driven. The membrane absorbs friction from the rotating action of the brush and is movable as wear occurs. The storage roll 10 and the collector roll 11 simplify this movement and permit the initial installation of an adequate supply of the membrane 9. The abrasive belt 6 is adapted to be pressed against a work piece by the action of a rotatable brush 12 exerting pressure on the upper surface of the abrasive belt 6. The brush 12 is mounted on a shaft on bearings 13 and is rotated by a wheel 14 and driven by a belt 15 from a suitable source of power, the belt receiving its drive action from a pulley wheel 16 and power drive 17.

The mounting of the brush 12 and its shaft 13 is at the end of a beam 18 which has a rigid connection with a lever 19 and which lever 19 is adapted to be moved by the action of a reciprocating piston, not shown, within a cylinder 20. The action of the cylinder serves to move the lever 19 by a piston rod 20a which is pivotally connected at 21 to the lever 19. In this backwards or forward movement of the lever 19, the lever and the beam 18 are rocked about a pivot point 22 which is fixed with respect to the main supporting frame (not shown).

A limit stop for controlling the extent of movement of the brush by limiting the swing of the lever 19 is provided by an adjusting screw 23 which impinges against the lever 19 and thus limits the downward pressure of the brush 12 on the work piece 4. The screw 23 is threaded in a fixed nut 24 which is mounted on the main frame (not illustrated).

Actuaton of the piston within the cylinder 20 is subject to the control of a limit stop device 25 and its arm 26 which latter is adapted to engage the work piece in the course of the movement of the work piece toward the right as indicated in the drawing. This equipment permits the sanding of narrow stock on either side of the machine. Two of these limit stops are provided, one at each side of the belt 6 (FIGURE 2).

The connection between the limit stop device 28 and the cylinder 20 may be by any convenient means as for example by electrical connections 27 controlling either pneumatic or hydraulic pressure to the opposite ends of the cylinder 20.

Among the advantageous features provided by the apparatus of this machine, it will be observed that a powered brush serves to reinforce the action of the abrasive belt and that the rotatable brush is not in contact with the abrasive. A further advantage results from the scratch pattern on the surface of the work which becomes variable with the speed of the brush. It is also to be noted that the effectiveness and aggressiveness is variable with the speed, stiffness and flexure of the brush.

It will also be noted that the rotation of the brush may be reversible to thus reduce aggressiveness.

It will be further noted that actuation of the brush in its contact with the membrane belt 9 is controlled by the work piece through the limit switch 25-26.

1. In a machine for abrading stock of the general character of wood, a feed belt for advancing a work piece, spaced rollers over which saidfeed belt extends, an abrasive belt, spaced rollers comprising a drive roller and a driven roller over which said abrasive belt extends and the runs of which are substantially parallel to the runs of said feed belt, a brush mounted between the upper and lower runs of said abrasive belt to exert pressure of said abrasive belt on said workpiece, and for -rotation on an axis transverse to the direction of movement of said feed belt, and power means for rotating said brush.

2. A machine of the type defined in claim 1 combined with support means for said brush pivotallyl mounted for raising or lowering said brush and increasing or decreasing the pressure of said abrasive belt on a work piece.

3. A machine of the type delined in claim 1 combined with support means for said brush pivotally mounted for raising or lowering said brush and increasing or decreasing the pressure of said abrasive belt on a work piece, and power driven linkage connected to said support means for actuating the same.

4. A machine of the type defined in claim 1 combined with support means for said brush pivotally mounted for raising or lowering said brush and increasing or decreas- 2 ing the pressure of said abrasive belt on a work piece, power driven linkage connected to said support means for actuating the same, and a limit switch controlled by movement of the work piece serving to operate said linkage.

5. In a machine of the type defined in claim 1 combined with a protective membrane extending between said brush and the non-abrasive side of said abrasive belt,

' and extending'-` between a supply roll to a collecting roll located between said drive and said driven rollers in a run parallel to the movement of said abrasive belt.

6. A machine of the'type defined in claim 1 combined with support means for said brush pivotally mounted for raising or loweringsaid brush and increasing or decreasing the pressure of said'abrasive belt on a work piece, power driven linkage connected to said support means for actuating the same, and a limit switch controlled by movement of the Work piece serving to operate said linkage, said switch including an arm pivotally mounted laterally with respect to said abrasive belt and adapted to swing' into the path of the work piece when the latter is moved by the feed belt.

References Cited UNITED STATES y PATENTS .829,191 8/1906 Yarnell 51-141 2,578,622 12/1951 Bader 5l-l48 2,923,103 2/1960 Cosmos s -4.--" 51-141 3,049,839 8/1962 .Smith 51-141 3,271,909 9/1966 Rutt 51-138 X 3,374,583 3/1968 Jacobi 51-141 3,408,775 11/1968 Rutt 51-141 X ROBERT C. RIORDON, Primary Examiner D. G. KELLY, Assistant Examiner U.S. Cl. X.R. 

